People are generally aware of the most common causes of hallucinations, like schizophrenia and a really high fever. But lesser known are the more rare causes; here are six you probably haven't heard about.

Benefits Of Being An Involved Father: Children Of Calm, Hands-On Dads Are Smarter, Says Study

Mother’s Day is coming up this weekend, but if you have an especially high IQ, you may want to get something for dad, too. A new study has found fathers have an important impact on their baby’s cognitive development, and those whose fathers were positively active during the first few months of birth, scored higher on cognitive tests by age 2.

The study, conducted at the Imperial College London, notes fathers who positively interact with their young children by playing with them and giving them positive feedback, help increase their offspring’s cognitive development. In fact, the researchers suggest it's able to predict a young child’s cognitive abilities by simply looking at how much good quality time they spent with dad.

“The clear message for new fathers here is to get stuck in and play with your baby,” said study author Professor Paul Ramchandani told The Independent. “Even when they're really young playing and interacting with them can have a positive effect.”

For the study, the ICL team looked at 128 fathers interacting with their three-month-old babies, recorded videos of the fathers playing with their children without toys, and watched the child-father pairs during book-reading sessions when the children were two-years old. The researchers also measured the toddler's cognitive development. Results revealed a positive correlation between the babies early relationship with their fathers and the children’s test scores later in life. Two factors seemed to have the strongest positive effect on the toddler’s cognitive skills: having a father with a calm demeanor, and having a father who spent quality time with them.

Of course, the study was only observational, and it’s not clear if a father’s interaction was the direct cause for these children’s cognitive abilities. The researchers explained that it may just be that children of interactive fathers generally have a more positive life and more opportunities than children with more absent fathers.

Still, this isn’t the first time scientists have noted the benefits of having a positive (and present) father figure. A 2002 study found similar results, revealing that children of more involved fathers were more likely to show cognitive competence and education success than those of less-involved fathers. In addition this same study showed that children of involved fathers were more likely to enjoy school and take part in more after-school activities.

In addition, a father’s interaction can also affect a child’s overall enjoyment of life, as a study from 2012 found that a father’s involvement in a child’s life, particularly a daughter’s life, was a strong predictor of her self esteem and life satisfaction in adulthood.